@conference {78978,
	title = {Prenatal maternal effects on daughter milk production in New Zealand dairy cattle},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {72},
	year = {2012},
	month = {Jan},
	pages = {19-22},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {<p>The impact of a cow{\textquoteright}s live weight and body condition score (BCS) during pregnancy on the milking performance of a resulting daughter was investigated using 4,021 Jersey and 9,329 Holstein Friesian dam-daughter pairs from the Livestock Improvement Corporation Sire Proving Scheme. Although the estimated maternal heritability of each trait in each breed was small (\&lt; 0.02), a l kg increase in dam weight was associated with 1.19 ({\textpm} 0.25) and 0.43 ({\textpm} 0.15) litres increase in daughter milk volume, a 61 ({\textpm}11) and 15 ({\textpm}6) gram increase in fat and a 55 ({\textpm} 8) and 14 ({\textpm}5) gram increase in protein in Jersey and Holstein Friesian cows respectively. A one unit increase in BCS was associated with an increase in volume by 32 ({\textpm} 19) litres in Jerseys and a 14 ({\textpm} 14) litre decrease in Holstein Friesians. Fat increased by 1.91 ({\textpm} 0.84) kg and 0.56 ({\textpm} 0.55) kg and protein increased by 1.64 ({\textpm} 0.63) kg and 0.06 ({\textpm}0.42) kg per unit BCS in Jersey and Holstein Friesian respectively. All daughter responses are per lactation. Although small changes in the daughters milking traits were observed, the lack of significant variation in the maternal heritability indicates that the sample size of the dataset may not be sufficient to detect if prenatal maternal effects truly exist.</p>
},
	issn = {1176-5283},
	author = {Gudex BW and Johnson DL and Singh K}
}
@conference {79016,
	title = {The use of milking intervals of individual cows in assessing herd test milk production data},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {72},
	year = {2012},
	month = {Jan},
	pages = {186-188},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {<p>Herd testing is a significant expense for dairy farmers but it gives important information about individual cow yields and contributes to the genetic worth status of the cows. While every effort is made to maximise the value of the tests to the farmer there are still opportunities to increase this value further. Estimations of milk yield from herd tests, whether from one or two milkings, rely on the generally held assumption that animals come in to the parlour in a similar order at each milking (DairyNZ 2011) and so the values obtained reflect a nominal 24 hour yield. ... continued</p>
},
	issn = {1176-5283},
	author = {Molenaar AJ and Henderson HV and ML Burgess and Burgess WG and Johnson DL and Singh K}
}
@conference {69523,
	title = {Deer Improvement{\textquoteright}s breeding scheme for venison production in red deer (Cervus elaphus)},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {70},
	year = {2010},
	month = {Jun},
	pages = {278-282},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {This paper describes the progress of the Deer Improvement breeding scheme that has been in place since 2004. The aim of the programme is to improve venison production through genetic selection for growth rate of lean meat with improved fertility, temperament and mature hind weight. The breeding programme currently comprises 500 hinds bred from stags selected for high growth rate with the intention of increasing hind numbers to over 1,000. This projected increase will be facilitated by the use of embryo transfer to multiply the genes of the top ranked yearling animals, thus shortening the generation interval. As part of the programme, all progeny are DNA parentage tested, weighed frequently during their first 12 months of life and temperament scored. Pregnancy and weaning rates are recorded in the nucleus and progeny testing herds. As a result of selection during the past six years, the average yearling weight has increased by 1.5 kg/yr over all farms involved in the breeding programme. In 2009, male fawns from the nucleus herd reached an average of 100 kg at seven months of age. This is greater than the current industry average of 75 to 78 kg for the same age.},
	issn = {1176-5283},
	author = {Quinn-Walsh EG and Johnson DL and Chardon J and Spelman RJ}
}
@conference {42057,
	title = {Testing for quantitative trait loci for lactation persistency in dairy cattle},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {107-110},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {Lactational persistency has not been selected for in New Zealand dairy populations. Existing milk production data and pedigrees from New Zealand Holstein-Friesian cattle at pasture, recorded in the Livestock Improvement Corporation database were utilized with a grand-daughter design, for a genome-wide search for a quantitative trait locus for persistency of lactation. Persistency was defined as a weighted sum of test-day yields. A significant region was identified in one grandsire family on Chromosome 3 at microsatellite marker position AGLA247 (chromosomal position 67cM; P <0.05). To verify this result, data from a research dairy herd defining persistency as the mean of three weekly tests of daily yield in March (late lactation) divided by the equivalent daily yields in October (early lactation)) for three seasons beginning in 1997/98 were used in a phenotypic association study on Chromosome 3 only. One allele of marker HUJ246, close to the original region appeared to show an additive effect. The maximal difference between this genotype and the others at this marker locus was 12.3 {\textpm} 4.4\% of the mean persistency. The potential use of this marker in the New Zealand dairy cattle population depends on the current allele frequencies in the industry. },
	issn = {1176-5283},
	author = {Morris CA and Spelman RJ and Henderson HV and Cullen NG and Hyndman DL and Miller FM and Johnson DL and Molenaar AJ and Grigor MR and Davis SR}
}
@conference {41744,
	title = {Effect of increased somatic cell count on lactation yields of milk , fat and protein},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {293-296},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {The purpose of this study was to estimate the effect of increased SCC on production in New Zealand dairy farms. Herd test data from lactations one through six were used in the study. Herd test milk, fat and protein yields were modelled as a function of days in milk at the time of the herd test and the logarithm (base 2) of SCC. The model estimates were used to obtain the predicted value for each observation using the actual log SCC and again where the log SCC was increased by one (i.e. doubling the SCC level). For first-lactation cows, the reduction in a 270-day lactation yield from a doubling of the SCC was estimated to be 78 litres, 2.39 kilograms and 2.04 kilograms for milk, fat and protein yield, respectively. Herd SCC level also influenced the extent to which a doubling of SCC decreased production. For first-lactation cows every doubling of SCC was predicted to result in an average loss of 67 and 90 litres in the lowest and highest quartiles, respectively.},
	issn = {1176-5283},
	author = {Winkelman AM and Montgomerie WA and Johnson DL}
}
@conference {41761,
	title = {Test-day model for national genetic evaluation of milk production traits},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {382-387},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {Genetic evaluation for milk, fat and protein yields, using 270-day lactation yields in an across-breed animal model (AM), has been performed in New Zealand since 1996. A new system has been developed to calculate breeding values from herd-test data. In the current AM, a 270-day lactation yield record is calculated based on 1 to 10 test-day records. The environmental effect of herd-test-day (HTD) is removed during the 270-day lactation yield calculation. However, this is done outside the AM, without reference to the genetic level of the HTD contemporary group. A test-day model (TDM) can simultaneously account for the fixed effects such as HTD contemporary groups,and the genetic, permanent environmental (PE) and temporary environmental randomeffects that affect the trait. By including the effect in the model, the TDM allows the environment specific to each test-day to be better taken into account, resulting in an improved accuracy of evaluation. A TDM can accommodate changes in the genetic and PE effects over time by fitting polynomials of time to these effects. A random regression (RR) TDM can accommodate changes in the genetic and PE effects overtime by fitting Legendre polynomials of days in milk (DIM) to these random effects. The RR TDM allows each cow{\textquoteright}s lactation curve to have a different shape. TDM evaluations are more stable than evaluations obtained using 270-day lactations because they account for genetic differences in maturity rate and persistency of lactation. The sire breeding values (BVs) from the TDM were compared to those from the AM. For sires with more than 30 daughters, the correlations between the BVs from the two models were 0.990, 0.988 and 0.990 for milk, fat and protein yields, respectively. The TDM demonstrated improved stability for sires undergoing their widespread proof. There was less variation in the change in BVs for reproof sires from August through to October compared to the AM. The sires that show the greatest change during early reproof under the AM were sires that were outliers for their TDM persistency breeding values for their breed.},
	issn = {1176-5283},
	author = {Harris BL and Winkelman AM and Johnson DL and Montgomerie WA}
}
@conference {41875,
	title = {Body condition score as a candidate trait in the breeding worth dairy index},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {103-106},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {Body condition score (BCS) has been proposed for inclusion in the New Zealand national dairy index, Breeding Worth (BW), to account for replenishment of body tissue. Currently, the breeding objectives model positively accounts for body tissue mobilisation (through extra yield), but not the negative cost of replenishing body tissue. Two methods have been proposed: 1) Including BCS directly into BW by calculating and assigning an economic value to BCS and 2) Adjusting liveweight Breeding Values (BVs) for BCS, which would mean that liveweight BVs would be expressed at a constant BCS (indirect method). Energy equations were used to calculate the direct economic value for BCS and included a sensitivity analysis. With an economic weight of $25, the percentage emphasis of BCS in BW would be 3.4\%. Including BCS in BW, either directly or indirectly, had little impact on sire rankings (rank correlations with and without BCS within breed were >0.99) and would only have a small impact on the economic response of BW ($0.02 net /cow/annum) and the improvement in BCS (0.006 BCS units/cow/annum). It is concluded that there would be little benefit to including BCS as an independent trait in BW. Body condition score is already included as a predictor in the genetic evaluation of fertility and breeding values for BCS will be estimated routinely from the fertility model.},
	issn = {1176-5283},
	author = {Pryce JE and Harris BL and Johnson DL and Montgomerie WA}
}
@conference {41617,
	title = {Responses and factors affecting intramammary infection rates resulting from infusion of a Streptococcus uberis strain in Friesian - Jersey crossbred cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {70-76},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {The objective of this study was to investigate responses to an intramammary infusion of a Streptococcus uberis strain in 264 Friesian-Jersey cows, and identify factors contributing to clinical mastitis risk in the week following infusion. Factors examined for their contribution to risk include sire, days in milk at the time of infusion, SCC on the morning of infusion, previous mastitis treatment history, and the presence of any major pathogens at the time of infusion. Prior to infusion, milk samples were collected from all glands for bacteriology assessment, and antibiotic treatments were administered to clear infections. A single gland from each cow was infused with an average 104 colony-forming units (sd=22) of Streptococcus uberis, and milk samples were collected at each milking for the subsequent 13 milkings, or until diagnosis of clinical mastitis. Logistic regression and survival analysis were used to determine risk factors. Findings showed that cows with a somatic cell count at infusion of >=100,000 cells/ml had a lower incidence of clinical mastitis (18.3\% vs. 81.5\%; p<0.0001). Results also indicated that the presence of Staphylococcus aureus at infusion for cows that had no pre-infusion mastitis treatment(s) was associated with a lower incidence of clinical mastitis (29.0\% vs. 82.8\%; p<0.0001). },
	issn = {1176-5283},
	author = {Sanders KM and McDougall S and Stanley GE and Johnson DL and Spelman RJ and Harcourt SJ}
}
@conference {41491,
	title = {Effect of timing of insemination of dairy cows with liquid semen relative to the observation of oestrus},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {64},
	year = {2004},
	month = {Jan},
	pages = {140-142},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {Many studies have confirmed that the best conception rates are obtained when cows are inseminated from mid to late oestrus. The conclusions of Trimberger, (1948) has led to the universally accepted AM - PM schedule for inseminating cows. The guideline suggests that cows found in oestrus during the AM period be inseminated at the following PM and the cows in oestrus at the PM be inseminated the following AM. Variations of this rule have been tested with single and multiple AI during oestrus periods and once daily AI after the AM milking with no adverse effect on conception rates. The objective of this study was to determine the effect of time of insemination on Non Return Rates (NRR{\textquoteright}s) in a sample of seasonal breeding New Zealand dairy cows submitted for insemination once a day after following the AM - PM guideline. Two hundred farms participated in this trial with over 12,000 animals representing Friesian, Jersey and Cross breeds were included in this dataset. The farmers were asked to keep accurate records on when cows were first detected in oestrus during the first two weeks of mating. There was no significant difference in 18 to 24 day non return rates for all cows observed in heat at the two time periods and inseminated the following AM (71.8\%, PM and 71.6\% AM respectively, p = 0.18). There was no effect of bulls or age of cows. A nominal effect of breed of cow was observed. In conclusion, there was no effect on NRR when cows were inseminated at the one time period after AM milking whether they were first observed in heat the previous PM or the AM just prior to insemination. },
	issn = {1176-5283},
	author = {Vishwanath R and Melis J and Johnson DL and Xu ZZ}
}
@conference {41490,
	title = {Factors affecting non-return rate in dairy cattle},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {64},
	year = {2004},
	month = {Jan},
	pages = {138-139},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {Non-return rate (NRR) to artificial insemination (AI) gives a measure of bull fertility early in the mating season. Calving rate can be biased due to culling and is available too late in the season to be useful for detecting sub-fertile bulls. A current limitation, in the New Zealand dairy industry, to calculating the NRR for bulls is that it is largely based on raw averages of binary data (returned or not) and using only qualifying matings. For example, for an 18-24 day NRR, a mating would qualify if the insemination occurred at least 24 days prior to the end of the observation period and this would utilise only about 42\% of the available mating information. Currently no account is taken of environmental factors that may affect NRR (e.g. region, breed of cow) and of the number of inseminations for each bull.
The variable of interest is the time interval between the mating date for a cow and an end-point. For a cow returning to service during the AI mating period, the end-point is the date of return to service. For non-returns within the mating period, the end-point is the final AI mating date for the herd. The former type of mating record is uncensored while the latter is a censored record in the sense that a possible return event may not be observed. },
	issn = {1176-5283},
	author = {Johnson DL}
}
@conference {41227,
	title = {Genetics of milk characteristics in New Zealand dairy cattle},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {318-319},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {Data collection was integrated with LIC{\textquoteright}s herd testing service using a sample of 102 herds involved in LIC{\textquoteright}s SireProving Scheme (SPS) in 1995. In addition to milk volumefrom herd testing, the concentrations of fat, crude protein(total nitrogen), casein, whey and lactose were determined.The data was collected from over 3,000 cows born in 1996and first calving in the 1998 spring season, these beingpredominantly the daughters of approximately 220 SPSbulls. The milk characteristics were measured at three herdtests on each cow, with each herd having a herd test in eachof the Sept/Oct, Nov/Dec and Jan/Feb periods. Hereafter,we refer to these three periods as stages of lactation.},
	issn = {1176-5283},
	author = {Johnson DL and Petch SF and Winkelman AM and Bryant M}
}
@conference {40763,
	title = {Estimation of lactation yield from repeated measures of test day yields},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {16-18},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Test day production records were combined into a measure of lactation  yield for the purposes of genetic evaluation of lactation production in dairy  cattle. The lactation yield estimation adjusts for test day environment,  standardises lactation length, takes account of culling and weights test day  records according to number of tests, stage of lactation at test and intervals  between tests. Any combination of tests can be used allowing for inclusion  of records in progress or incomplete lactation in genetic evaluation. },
	issn = {1176-5283},
	author = {Johnson DL}
}
@conference {40770,
	title = {Genetic parameters for fertility traits in seasonal dairy cattle},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {38-41},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Genetic parameters for female fertility traits in New Zealand dairy  cattle have been estimated using a data set of herds participating in the  Livestock Improvement Sire Proving Scheme. In total, 66294 records of  both pure and crossbred Friesian, Jersey and Ayrshire cows in their first  lactation were used. The highest heritability estimates were .134, .058, .037, .037, .029 for age at  calving (AC), interval from start of mating (STOM) to first mating (SMFM),  interval from STOM to conception (SMCO), pregnancy rate at day 21 or 42  after STOM (PR21) or (PR42), respectively. Low heritabilities were  obtained for first mating to conception (FMCO), calving interval (CI) and  number of services (NS) (<.017). Genetic correlations between CI and either  SMFM or SMCO where high (.920 or .957). Genetic correlation between  SMCO and PR21 or PR42 is close to one. Therefore the later three traits are  identical from the selection point of view. For AC, genetic and phenotypic  correlations with milk production traits were high and unfavourable.  Antagonistic genetic correlations also existed between milk yield and the  fertility traits and between SMFM, SMCO, FMCO or NS and fat or protein  yield. The unfavourable genetic correlations between milk production and fertility  traits strongly suggest that fertility performance should be incorporated into  the breeding objectives of New Zealand dairy cattle. Based on their  heritability estimates, their genetic coefficients of variation and their genetic  correlations with production and other fertility traits, it is recommended that  SMFM and PR21 (or its more easily obtainable equivalent trait 2-to-24-day  non-return rate, 2-24NRR) should be used as selection criteria. In addition,  the incidence of use of treatment programmes for overcoming fertility  problems, such as induction of calving and anoestrus treatment, should also  be incorporated into the selection index.},
	issn = {1176-5283},
	author = {Grosshans T and Xu ZZ and Burton LJ and Johnson DL}
}
@conference {40719,
	title = {Seasonal changes in LH profiles of ewes selected for and against an early lambing date},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {224-227},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Smith JF and Briggs RM and Parr J and Johnson DL and Duganzich DM}
}
@conference {40512,
	title = {The date of onset of puberty in ewe lambs as an indicator of the ability to breed out-of-season},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {299-302},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Half-sib heritability estimates were derived from ewe lamb progeny of the Woodlands Romney selection project. Ultrasonic subcutaneous fat depths (C) were measured with a Delphi probe at 5, 6, 8 and 14 months of age.  Heritability estimates at each age were 0.31 (SE=0.12), 0.45 (0.11), 0.29 (0.06) and 0.28 (0.09) respectively. A Toshiba Sonolayer SAL-22A B-mode ultrasonic scanner was used to measure muscle width (A), depth (B) and GR tissue depth at 14 months of age and resultant heritability estimates were 0.07 (0.05), 0.26 (0.09) and 0.39 (0.11), respectively. Genetic correlations among ultrasonic fat depths at different ages ranged from 0.81-0.95 (SE 0.06-0.12) with higher values for those of closer temporal separation. Phenotypic correlations were consistently about 0.3 below the corresponding genetic correlations. Ultrasonic GR had a high heritability estimate and a high genetic correlation with fat depth at 14 months of 0.84 (0.08),but its genetic correlations with fat depths at earlier ages, were lower ranging from 0.55 to 0.72. The genetic correlation of hogget fleece weight with fat depth at 8 months of age was 0.09 (0.15), and the genetic correlation between 8 month liveweight and fat depth was 0.38 (0.13); similar relationships were found for fat depths measured at other ages. The heritability estimate for muscle depth B was moderate and close to that reported for carcass measurements. In contrast, the estimate for muscle width A was lower than reports for carcass measurements perhaps reflecting limitations in the ultrasonic technology used. The results indicate that ultrasonic measurements are useful selection criteria in breeding programmes to alter carcass traits.},
	issn = {1176-5283},
	author = {Smith JF and Parr J and Johnson DL and Duganzich DM}
}
@conference {40496,
	title = {An investigation of sire by location interactions for faecal nematode egg counts in lambs},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {231-234},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The aim of this study was to gain evidence that the FecB and FecXI genes influence ovarian development in foetal life. Foetuses which were homozygous carriers of the Booroola gene (BB), Inverdale gene (II), heterozygous carriers of the Inverdale gene (I+) and non-carriers of both the Booroola (++) and Inverdale genes (++) were recovered at days 40 or 90 of gestation. To eliminate the effects of litter size in the Booroola study, equal numbers of BB and ++ embryos were transferred to recipient ewes.  Subsequently no gene-specific differences in litter size were noted at the equivalent of days 40 and 90 of gestation. From these studies the FecB gene was shown to affect body weight, the weight of the mesonephros, and development of germ cells. In essence, at day 40 the mean body weight and mean weight of the mesonephros were lighter in the BB foetuses compared to the ++ animals (P<0.05). Moreover the development of the BB ovaries appeared to be retarded relative to that of the ++ ovaries with respect to mitosis and meiosis of germ cells and also the timing of germ cell atresia. In the Inverdale foetuses, which were recovered after natural matings, differences were observed at the level of the ovary but none were noted with respect to body weight, or weight of mesonephros. At day 40 of gestation the ovaries of the putative II foetuses were significantly lighter (P<0.05) than those of the I+ or control animals. Moreover at day 90 the ++ and putative II ovaries contained significantly fewer (P<0.05) germ cells (i.e. ~110,000) compared to those in the authentic or putative I+ animals (i.e. ~240,000).  The differences in either the Booroola or Inverdale foetuses were not accompanied by any significant differences in plasma or pituitary concentrations of follicle-stimulating hormone or plasma inhibin. The results are consistent with the notion that the FecB and FecX genes influence ovarian development in foetal life.},
	issn = {1176-5283},
	author = {Morris CA and Bisset SA and Baker RL and Watson TG and Johnson DL and Wheeler M}
}
@conference {40529,
	title = {Plasma prolactin in Romney sheep selected for hogget fleece weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {371-376},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Seventy nine mature, alpacas were scanned every 10-14 days using real time ultrasonography to visualise the foetus. There was a 24\% foetal loss between days 21-30 of gestation and parturition, with the maximum loss occurring between days 21-30 and days 31-40 of gestation. There was a 5\% loss of foetuses after day 100 of gestation.},
	issn = {1176-5283},
	author = {Clarke JN and Pearson AJ and Sumner RMW and Johnson DL and Dobbie JL and Wildermoth JE and Wrigglesworth AL}
}
@conference {40514,
	title = {Relationships between loose wool bulk and follicle and fibre characteristics in yearling Perendale sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {307-310},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Progeny test mating was carried out for 7 high fleece weight (HFW) and 5 random control (RC) sires from the Woodlands breeding flocks in 1987, and for a 4 HFW sires in 1988. In 1990, 8 of the surviving HFW sires were backcross mated to their daughters (born in 1987 and 1988). There was no evidence for any of these sires being heterozygous, or for any of the sires involved in the backcross being homozygous, for a major gene which affects either fleece weight or liveweight.},
	issn = {1176-5283},
	author = {Sumner RMW and Stobart RH and Johnson DL}
}
@conference {40541,
	title = {Selecting on pubertal traits to increase beef cow reproduction},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {427-432},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Two groups of 10 mature, crossbred cows received either a single  daily dose of 10 g Mg or no supplemental Mg for two 5 day periods. Blood  was sampled twice daily and urine once daily. On 3 days blood and urine  were sampled four times. Serum Mg levels of 3 unsupplemented animals fell  from 0.74 },
	issn = {1176-5283},
	author = {Morris CA and Bennett GL and Johnson DL}
}
@conference {40527,
	title = {Selection programmes for nematode resistant sheep in commercial flocks},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {359-362},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {An experiment was established at Waikeria, near Te Awamutu, to select for pubertal traits in Angus cattle, with selection first applied to the animals born in 1982. The aims of this paper are to report on genetic parameters for age at first oestrus (AFO) in heifers, weight at first oestrus (WFO) in heifers, scrotal circumference (SC), 13-month weight (W13) and calving day (CD), to compare the performance of young animals in the selection and control herds, and to assess prospects of achieving a correlated response in calving rate.  Three selection herds and a control were set up, with single selection objectives being SC, AGE+ and AGE-, where {\textquoteright}+{\textquoteright} and {\textquoteright}-{\textquoteright} indicate selection for greater or lesser AFO. Phenotypic coefficients of variation were 15\% for AFO, 11\% for WFO, 8\% for SC, and 8\% for W13. Corresponding heritability estimates from Waikeria were 0.15, 0.30, 0.24 and 0.33, compared with those from other New Zealand research herds which averaged 0.34, 0.37, 0.38 and 0.36 respectively. The genetic correlation estimate for AFO and SC was - 0.81},
	issn = {1176-5283},
	author = {Watson TG and Hosking BC and Johnson DL and Hurford AP}
}
@conference {40395,
	title = {Genetic parameters and performance of flocks selected for advanced lambing date},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {52},
	year = {1992},
	month = {Jan},
	pages = {129-132},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Timing of the LH peak and ovulations in superovulated Coopworth  ewes synchronised with progesterone-containing CIDR},
	issn = {1176-5283},
	author = {Smith JF and Johnson DL and Reid TC}
}
@conference {40330,
	title = {Computer software to increase the efficiency of the New Zealand sheep industry},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {299-302},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Loose wool bulk has been identified as a desirable objective  characteristic associated with superior end-product performance in many  of the present uses of wool. These are specifically, improve appearance  retention of carpets and improved insulation of knitting yarns and loose  wool batts. Breeds have been shown to differ in their ability to  produce high bulk wools. Loose wool bulk is strongly inherited in the  adult fleece, it is not however expressed in the lamb fleece and  subsequently cannot be used as a selection criteria until hogget  shearing. Fibre crimp appears to be the major factor associated with  bulk. Crimp formation in Merinos is related to follicle structure, cell  mitotic activity and cellular differentiation within the follicle bulk  resulting in the production of different cortical cell types. At this  time it is not known if a similar situation applies to crossbred wool  type sheep. The identification of a suitable measurable structural  characteristic would facilitate the selection of high loose wool bulk  crossbred wool type sheep at a young age.  },
	issn = {1176-5283},
	author = {Binnie DB and Clarke JN and Cooke AC and Johnson DL and Rae AL}
}
@conference {40186,
	title = {Inheritance of loose wool bulk},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {49},
	year = {1989},
	month = {Jan},
	pages = {297-302},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The digestive efficiency of deer, goats and sheep fed on chaffed   lucerne hay was compared during summer (S) and winter (W). VFI, rumen   pool size and rumen ammonia concentration showed seasonal cycles in red   deer, with maximum values in S and minimum values in W, whereas rumen   FOR showed lower values in S than in W, especially for particulate   matter. Despite an increase in VFI, deer were thus able to maintain DM   and fibre digestibility in S, due to simultaneously increasing rumen   size and reducing outflow rate. Goats showed higher fibre digestibility   relative to sheep, associated with a larger proportion of small   particles in rumen digesta. Goats also had the highest rate of rumen   ammonia production. Relative to goats and sheep, deer showed very low   levels of VFI and rumen pool size in W, emphasising the importance of   understanding the factors controlling winter inappetence in red deer,   whilst the superior fibre digesting capability of goats suggests they   could be most efficiently used to utilise low quality fibrous feeds.    },
	issn = {1176-5283},
	author = {Sumner RMW and Clarke JN and Johnson DL}
}
@conference {40167,
	title = {Technical aspects of the Animalplan system},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {49},
	year = {1989},
	month = {Jan},
	pages = {197-202},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The relationships between sward height, bite dimensions and bite weight for one-year-old Friesian steers and bulls were examined. Eighteen turfs of uniform area of each of 3 pasture heights (5, 10, 15 cm) were cut from a ryegrass dominant sward in early spring and placed in polystyrene boxes. Sward height was measured prior to grazing and swards trimmed where necessary so that height in the surface horizon was uniform. The turfs were offered over 3 days to 3 bulls and 3 steers in a latin square design so that each animal had 20 bites of a turf of each height daily. Turfs were weighed to the nearest 0.1g before and after grazing. The height of grazed tillers was measured and all pasture was then removed above this height. The turf was then reweighed. Bite weight, depth, volume and area were then calculated for the steers and bulls. There was no significant difference between bulls and steers in bite dimensions. Sward height, which determines bite depth, appears to be the major determinant of bite weight and consequently of daily intake. The technique described has proved to be extremely useful in the study of specific sward structures and their effect on intake.},
	issn = {1176-5283},
	author = {Johnson DL and Rae AL and Clarke JN}
}
@conference {40030,
	title = {Artificial insemination in sheep - comparison of storage time, dose rate and insemination technique},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {46},
	year = {1986},
	month = {Jan},
	pages = {229-232},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {In 1984 selected Oxford Down (O) and Texel (T) sheep in Denmark and T and Finnish Landrace (F) sheep in Finland were purchased or leased and then assembled for treatment. The ewes were synchronised and superovulated before being subjected to surgical embryo recovery. Recovered embryos with at least 8 cells and intact zona pellucida were then deep frozen. The mean ovulation rate, number of eggs recovered and embryos frozen from the O and T in Denmark were 5.4, 4.4, 1.5 and 7.1, 5.0 and 3.0, respectively. Results for T and F in Finland were 7.5, 4.9, 4.1 and 10.0, 7.0 and 5.8, respectively. A total of 548 embryos was imported into New Zealand. Two-hundred and twenty embryos were thawed and transferred to Coopworth recipients in March and 46 in May 1985. The percentages of embryos surviving to term for the various breeds in March and May were: Denmark 0, 43 and 20; Denmark T, 59 and 7; Finland T, 59 and 55; Finland F, 64 and 50, respectively. Thirty-two Coopworths were inseminated with thawed F sperm deposited via endoscopy and 24 (75\%) lambed producing 28 lambs. The importation of both embryos and semen was very successful.},
	issn = {1176-5283},
	author = {Harvey TG and Johnson DL and Baker RL and Trust BK and Thomson BC}
}
@conference {39996,
	title = {Evidence of genetic improvement in the Angus Breeding Scheme of the Department of Lands and Survey},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {46},
	year = {1986},
	month = {Jan},
	pages = {67-70},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The relative importance of the currently recorded large number of descriptive conformation traits and of milkfat yield on retention for a second lactation of 6645 Friesian-sired and 5709 Jersey-sired heifers was examined. In a linear multiple regression model, the effect of heifers deviating from the {\textquoteright}normal{\textquoteright} conformation for a certain trait on the retention rate was used as an indicator for the relative importance of the trait. Milkfat yield was by far the most important trait for both breeds. Only a small number of conformation traits describing udder and teats influenced the retention rate significantly. The farmer with Jersey cows appeared to consider more conformation traits as important than the owner of Friesian cows. The results suggest the inclusion of only the important conformation traits describing udder and teats as potential traits in the selection of profitable dairy cattle in New Zealand to retain a high genetic response for milkfat yield.},
	issn = {1176-5283},
	author = {Nicoll GB and Johnson DL}
}
@conference {40002,
	title = {Repeatability of reproductive performance following active immunisation of ewes},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {46},
	year = {1986},
	month = {Jan},
	pages = {101-104},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The New Zealand sheep industry has been supported by a national sheep recording scheme, Sheeplan, for nearly 20 years. Sheeplan is directed towards genetic improvement of the national sheep flock. Its personnel have recently prepared a plan for future development which aims to extend the scope of the scheme, the accuracy of selection decisions made and the flexibility and efficiency of the recording service. It is proposed that the improved scheme be developed under Sheeplan{\textquoteright}s existing organisation as a centralised recording scheme and that restructuring of the data storage and data processing system be undertaken to enable Sheeplan to develop the following specific areas: improved adjustments for non-genetic factors; greater breeding value accuracy; development of across-flock relationships among animals; extension of the Sheeplan database; establishment of an industry-wide database; improved operational efficiency; accommodation of electronic developments for data collection and transmission; provision of opportunities for data analysis; and improve documentation of the scheme. The estimated financial benefit of implementing the plan is a doubling of the annual return to the sheep industry, from $9.6 million from the current Sheeplan to $19.7 million. This is achieved through a 40\% increase in accuracy of selection decisions; a 10\% increase in Sheeplan membership; and a 30\% increase in effective use of Sheeplan records.},
	issn = {1176-5283},
	author = {Clarke JN and Smith JF and Johnson DL}
}
@conference {39979,
	title = {Inheritance of loose wool bulk in Romney and Perendale sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {45},
	year = {1985},
	month = {Jan},
	pages = {213-216},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Lifetime performance data were collected from flocks of 200 mixed-age Romney, Coopworth and Perendale ewes at Whatawhata Hill Country Research Station which were shorn either once yearly in November or twice yearly in May and November beginning in 1978, together with the lifetime performance data of 2-year-old replacement ewes entering these flocks in 1979 and 1980. Twice-shorn ewes were consistently heavier after shearing in November with an apparent carryover effect the following May. More of the twice- shorn ewes required dagging before shearing in November. There was a significant frequency-of-shearing x breed interaction for both total greasy and total clean wool production. Twice-shorn Romney and Perendale ewes grew more wool than once-shorn ewes. Wool growth of the Romney was greater following shearing in May compared with the other 2 breeds. Frequency of shearing did not affect ewe survival, number of lambs born, lamb survival, or weight of lamb weaned per ewe. Incidence of casting was insignificant. Average net wool returns were greater for once-shorn ewes.},
	issn = {1176-5283},
	author = {Bigham ML and Sumner RMW and Clarke JN and Johnson DL}
}
@conference {39869,
	title = {Synchronisation and artificial insemination of ewes - techniques which have possible commercial application},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {44},
	year = {1984},
	month = {Jan},
	pages = {7-10},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Mature ewes, 110 to 125 days pregnant, had catheters surgically implanted into maternal and foetal blood vessels and electrodes sutured to the myometrium. Electromyographic (EMG) signals were amplified, rectified, integrated and recorded. Between 2 and 12 days before parturition, the EMG pattern comprised bursts of activity that lasted 6.3 },
	issn = {1176-5283},
	author = {Harvey TG and Johnson DL and Tervit HR and Welch RAS}
}
@conference {39790,
	title = {Evaluation of dam breeds and crosses for export lamb production},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {42},
	year = {1982},
	month = {Jan},
	pages = {133-136},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The effects of castrating and surgically dehorning male Drysdale and Tukidale lambs at birth or docking on subsequent horn growth were investigated in 3 lamb crops at Whatawhata Hill Country Research Station. Castration was more effective than dehorning in reducing subsequent horn growth. A combination of castration at birth and dehorning at docking was the most effective way to treat lambs to reduce horn growth. Excision of germative tissue around the base of the horn following dehorning increased the effectiveness of dehorning. Attainment of meat inspection standards for horned breeds is more dependent on the "trimmers" on the slaughter chain than the time of dehorning.},
	issn = {1176-5283},
	author = {Clarke JN and Atkins KD and Geenty KG and Johnson DL and Hickey SM and Wilson JA}
}
@conference {39755,
	title = {Level of nutrition of the ewe and lamb survival},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {42},
	year = {1982},
	month = {Jan},
	pages = {13-14},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {No abstract supplied},
	issn = {1176-5283},
	author = {Johnson DL and Clarke JN and MacLean KS and Cox EH and Amyes NC and Rattray PV}
}
@conference {39787,
	title = {Relationships of carcass conformation of cattle and sheep with carcass composition},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {42},
	year = {1982},
	month = {Jan},
	pages = {125-126},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Hemicastrates and steers were slaughtered at similar carcass weights at 14, 18 and 22 months of age for the assessment of factors associated with tenderness difference in representative forequarter muscles. Objective tests indicated that hemicastrate meat was tougher than that from steers at 22 months of age only. Heat labile collagen content was the major parameter associated with tenderness in M. longissimus; in both M. splenus and M. triceps brachii it was sarcomere length.},
	issn = {1176-5283},
	author = {Bass JJ and Johnson DL and Woods EG and Moore RW}
}
@conference {39696,
	title = {Liveweight variation in Sheeplan flocks},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {40},
	year = {1980},
	month = {Jan},
	pages = {254-257},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Johnson DL and Clarke JN and Robinson CA}
}
@conference {39641,
	title = {Beef breed evaluation - breed utilization strategies},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {39},
	year = {1979},
	month = {Jan},
	pages = {223},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Johnson DL and Morris CA}
}
@conference {39637,
	title = {Interrelationships between GR and other lamb carcass fatness measurement},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {39},
	year = {1979},
	month = {Jan},
	pages = {194-201},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Kirton AH and Johnson DL}
}
@conference {39501,
	title = {Selection Indices for Perendale Sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {36},
	year = {1976},
	month = {Jan},
	pages = {23-29},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Elliott KH and Johnson DL}
}
